1. Field of the Invention
The present disclosure relates to electrical machines, and more particularly to rotating transformers for wound field synchronous machines.
2. Description of Related Art
Electrical machines such as wound field synchronous generators and wound field synchronous motors include rotating and stationary parts. Typically, the rotating part includes field windings configured for rotation relative to armature windings arranged on the stationary part. In the case of wound field synchronous generators, a current flow through the field windings generates a magnetic field. As the rotating part rotates about the armature windings the magnetic field induces current flow in the armature windings, thereby converting mechanical rotation into electrical energy. In the case of wound field synchronous motors operation is reversed. Current flow to the armature windings generates a magnetic field. The magnetic field pushes a magnetic field excited into the field windings, thereby generating an electromagnetic torque that mechanically rotates the rotating part of the motor.
In both types of electrical machines, the rotating parts of the machine need communicate with the stationary part of the machine. The communication is typically in the form of electrical energy transferred from the stationary part to the rotating part of the machine, such as exciter current for main field windings. Typically, mechanical devices effect communication between the rotating and stationary parts of the electrical machine, such as through contacts, cables or slip rings. Alternatively, winding and armature sets can effect communication between the rotating and stationary parts of electrical machines.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for apparatus and methods for providing communication between rotating and stationary parts of electrical machines. There is also a continuing need to transfer electrical energy between rotating and stationary parts of electrical machines that is efficient, suited for high frequency and/or power, and which is light weight and contactless. The present disclosure provides a solution for these problems.